"The Prophet 5 contains five individual voices. For its principal sound sources each voice contains two VCO's (voltage controlled oscillators), OSC A and OSC B, and a white noise source which can be mixed into a resonant low-pass VCF (voltage controlled filter). The filter modifies the voice timbre under control of its four-stage envelope generator. The filter may also be resonated and serve as a sound source. Following each filter, a VCA (voltage controlled amplifier), also controlled by a four-stage envelope generator, shapes the voice amplitude. Supplementing the basic voices are polyphonic modulation (POLY-MOD) signal routings within each voice that allow OSC B and the filter envelope generator to function as modulation sources applied to OSC A frequency or pulse width, or the filter frequency. Finally, there is a single LFO (low-frequency oscillator) and a pink noise source which can be mixed to modulate all five voices, as adjusted by the MOD wheel.

"The Prophet-5 sustained six revisions (or revs). Rev 1 was the original design. Rev 2 was a refinement of the original design and largely transparent. Rev 3, however, was a vastly different synthesizer than Revs 1 and 2. Introduced to Rev 3 were new voltage controlled IC's (CEM), an improved ADC, DAC, and a different control voltage distribution scheme. More sophisticated editing and tuning routines were designed, and to improve servicibility, voice trimmers were reduced from 80 to 45. Some believe that the Rev 3 synthesizers are slightly inferior (sonically) to their predecessors by revealing an absence in the lower frequencies. While this may be true, the majority of the Rev 3 synthesizers are far more operationally stable than their Rev 1 and Rev 2 counterparts.

"Instrument codes are coded by model number, followed by a period and then the rev level.

Comparing the Rev2 to the Rev3

Revision2The Rev1 and Rev2 are drastically different synthesizers from the later model Rev3's and above. Below is a brief glance at some of the differences between the panels as seen on the Rev2 (pictured here) and the Rev3's pictured above.

Preset button absent on rev3. Notice worn label reading "from tape". This button was used with the "preset" button in the Modulation Section to double as cassette interface switches (after manufacturer's upgrade).

Amplifier Section

Different location of master volume knob

Lack of dedicated cassette interface section

Edit button: later models had instant editing and therefore don't have this button. Instead, Rev3's have the A440 tone button next to the "Master Tune" as well as the "Tune" button, to initiate auto-tuning (with a light in it).

-this information and these images were provided by the owner of this Rev2, David Bellamy of Northants, England